Differential letter spacing for typewriters



Oct. 13, 1942. c. w. NORTON 2,298,805

DIFFERENTIAL LETTER SPACING FOR TYPEWRITERS Filed June 25, 1959 10 Sheets-Sheet 1 .7 I I l 1 I I I l 1 A I l l I u INVENTOR [Zr/2 1w limb/inn BY MMAM 1. i ATTORNEY:

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Oct. 1.3, 1942. c. w. NORTQN DIFFERENTIAL LETTER SPACING FOR TYPEWRITERS File d June 25, 1939 10 Sheets-Sheet 2 I INVENTOR [/1 r5; [MM/i011,

BY M flab M ATTORNE Oct. 13, 1942. c, w. NORTON DIFFERENTIAL LETTER SPACING FOR TYPEWRIT-ERS l0 Sheets-Sheet 5 Filed June 23, 1939 Oct. 13, 1942.

C. W. NORTON DIFFERENTIAL LETTER $PACING FOR TYPEWRITERS Filed June 23,v 1939 10 Sheets-Sheet 4 Mb INVENTOR Mar 6/ fiffloriaiz My 5 AM ATToRNizYs 4, 4 ,lv z mg mmw 0 mm" 9E 0 4% 6 gr 220E7 Oct. 13, 1942; c. w. NORTON 2,293,805

DIFFERENTIAL LETTER SPACING FOR TYPEWRITERS Filed June 23, 1939 10 Sheets-Sheet. 5 v

INVENTOR i (/zarlw' Hilario?? BY P zfi gATToRNgYfY i v Oct. 13,1942. "c. w. NORTQN 2,298365 DIFFERENTIAL LETTER SPACING FOR TYPEWRITERS Filed June 25, 1959 10 Sheets-Sheet 8 4 INVENTOR ATTO R N EYS Oct. 13, 1942.,

C. W. NORTON DIFFERENTIAL LETTER SPACING FOR TYPEWRITERS Filed June 25, 1959 10 Sheets-Sheet 9 AAAWWWTTT LL.- -SPA CING CAR FIG. CARFIG. CAPFIG. CAR FIG. CAPFIG. CARFIG.

I X x X X X 1 II X x x x X x X x I! x x) ,x x x x x x I x x x INVENTOR I Mar/er W/Vflllfii BY M ATTORNEYS Oct. 13, 1942. c'. w. NORTON 2,293,805

DIFFERENTIAL LETTER SPACING FOR TYPEWRITERS Filed June 23, 1959 10 Sheets-Sheet 10 FIG. UNITS INVENTOR ATTORNEYS Patented Oct. 13, 1942 UNITED STATES PATENT OFFICE DIFFERENTIAL LETTER SPACIN G FOR TYPEWRITERS Application June 23, 1939, Serial No. 280,708

9 Claims.

The present invention relates broadly to typewriting machines and more especially to letter spacing mechanisms to control carriage movement.

The invention is embodied in a construction adapted more especially for the Varityper machine, wherein the printing type is carried upon a shuttle movable over an anvil, and is struck by a printing hammer.

The present invention provides a typewriter construction whereby differential letter spacing mechanism is capable of cooperating with type fonts of different sizes, or, stating the fact in different language, the differential letter spacing mechanism is applicable to different standard carriagespacings, asfor example, ten spaces, twelve spaces, or fourteen spaces to the inch. It is to be understood that other standard carriage spacings may also be equally Well adapted to the present differential letter spacing construction.

The differential letter spacing mechanism of the present invention is constructed to operate through permutations and combinations of a plurality of escapement mechanisms operating on other to obtain the required carriage movements to cause the typed page to have the same appearance as the page printed from typographers type, set in the usual manner well knownin the printing art wherein there is a predetermined distance between the letters of a word.

The disclosure herewith is illustrative of the preferred form of the invention, but it will be apparent that the invention is not limited to any particular kind of typewriting machine since 1 many features of the invention may be applied predetermined arbitrary units; for example, the f i operation of escapement If will permit carriage movement of one unit; escapement II will allow the carriage to move two units; and escapement IV-f will permit a carriage movement of four units. Thus, by simultaneously operating escapements If and II three units of carriage movement are obtained; by simultaneously operating escapements I-f and IV-f, six units of movement are obtained, and by simultaneously type fonts as A, B, C, D etc.) type font A may arbitrarily be said to require a setting of normal carriage spacings to ten spaces to the inch; type font B a setting of twelve spaces to the inch; type font C a setting of fourteen spaces to the inch; type font D a spacing of For exwith equal facility to different. forms of typewriter mechanisms. It, therefore, follows that the disclosure herewith is understood as being illustrative of the preferred form of the invention and is not to be considered in a limiting sense. Throughout the detailed specification and drawings, like parts are designated by like characters.

Fig. 1 is a plan view of the preferred form of typewriting machine with such parts omitted as are well known in the art and may not be necessary to a complete understanding of the present invention.

Fig. 2 is a longitudinal vertical sectional view taken on line 2-4 of Fig. 1.

Fig. 3 is a detail elevational view taken on line 33 of Fig. 1 and illustrates the mechanism controlled by the shift keys for changing the effect of the type key levers relative to the differential letter spacing mechanism.

Fig. 4 is a detail view illustrating the effect of the depression of the Cap shift key relative to the letter L key of thekeyboard.

Fig. 5 is a detail view illustrating the effect of the Fig. shift key on the effective operation of the letter L of the keyboard.

Fig. 6 is a plan view detailed section on line 6--6 of Fig. 3 and illustrates the relation of the key push rods to the three universal bars that control the differential letter spacing.

Fig. 7 is a detail section on line 'l'l of Fig. 6 and illustrates the relation of the push rods carried by the type keys to the three universal bars.

Fig. 8 is a view looking from the rear toward the front of the machine at the end of the escapement shaft and shows the escapement wheel I] which, when operated, permits the carriage to escape one unit. The escapement dogs are shown in normal position with the carriage stationary.

Fig. 9 is a detailed view of the escapernent dog and a portion of the escapement Wheel If when a type key lever has been depressed and shows the movable dog as disengaged from the teeth of the escapement wheel If.

Fig. 10 is a sectional view on line |8l9 of Fig. 13 and illustrates the escapement wheel II-f and its connected gearing with the escapement dogs thereof in normal position with the carriage stationary. This escapement wheel II--f permits the movement of two units to the carriage when a key lever is depressed.

Fig. 11 is a view taken on HH of Fig. 13 and illustrates in the foreground a ratchet wheel for normally preventing backward rotation of escapement wheel IV-j when the carriage is returned. The escapement IVj allows a carriage movement of four units when a type key lever is depressed.

Fig. 12 is a sectional View On line l2l2 of Fig. 13 and illustrates a cross-section through escapement wheel IV-f together with the connected gearings connecting this escapement wheel to the escapement shaft.

Fig. 13 is a sectional view through the differential escapement mechanism on line |3i3 of Fig. 8.

Fig. 14 is a plan View of a part of the escape ment dogs for the three escapement Wheels taken on line 14-44 of Fig. 13.

Fig. 15 is a detailed sectional view on line |5I5 of Fig. 2 and shows one of the drive gears which connect the escapement shaft with the carriage rack. It also illustrates the nose of the holding dog which operates to hold the carriage rack stationary when the carriage spacing is changed from one normal or standard carriage spacing to another.

Fig. 16 is a detailed view illustrating the holding dog for the carriage rack which operates to hold the carriage stationary when the control for the carriage spacing is changed from one standard spacing to another and is taken on line l6l 6 of Fig. 1.

Fig. 17 is an elevational detailed view illustrating the key controlled release mechanism for the hammer which drives the paper against the type to produce the printing impression and is a view taken on line l1--I l of Fig. 18.

Fig. 18 is a detailed view of the hammer release mechanism and is taken on line I8l8 of Fig. 2 and also line I8l8 of Fig. 17.

Fig. 19 is a detailed view taken on line i9-l9 of Fig. 18.

Fig. 20 is a detail view taken on line 2El20 of Fig. 17.

Fig. 21 is a detail view illustrating the push rod controls relative to the type key L, in their relation to the three universal bars.

Fig. 22 is a detail view of the push rod associated with the period key and showing this type key operative only on the middle universal bar.

Fig. 23 illustrates the relation of the push rods carried by the letter key A and showing in dotted lines the effect of the shift keys on these push rods in their relation to the three universal bars.

Fig. 24 illustrates the push rods connected with the W key and showing in dotted lines the effect of the operation of the shift keys on these rods relative to the universal bars.

Fig. 25 illustrates the push rods connected with the T key and shows in dotted lines the effect of the shift keys in moving these rods relative to the three universal bars.

Fig. 26 illustrates the push rod associated with the spacing key and shows this rod as applicable to one only of the three universal bars.

27 is a diagram showing the relation of the letters in words when written with a typewriting machine having ordinary constant letter spacing for the carriage.

Fig. 28 is a diagram illustrating the same words as shown in Fig. 27 when these words are written on a machine equipped with the present invention.

Fig. 29 is a diagram illustrating the relation of the various push rods relative to certain letters and characters in their association with the universal bars when either one of the three characters controlled by each type key lever is presented at the printing point.

Fig. 30 is a table showing the units of escapement movement allowed by the carriage for each letter or character designated in the table.

Fig. 31 is a table similar to Fig. 30 except that the table of Fig. 31 deals with the characters on the type keys.

Fig. 32 is a diagrammatic view illustrating the relation of priting type to the center of the printing point.

Before describing the constructions in detail, a general outline of the invention will be given in order that the specific descriptions which follow may be more easily understood.

The tables shown in Figs. 30 and 31 designate the carriage movement (as measured in arbitrary units) for each letter and character that the machine is capable of printing. The actual width of each letter or character (with the exception of punctuation marks) is one-quarter unit less than the amount of carriage movement allowed for such letter or character. The front edge of each character or letter is always a constant distance from the center of the printing point regardless of the actual width of the letter or character. Since the letter or character (with the exception of punctuation marks) is one-quarter unit less than the carriage movement allows, the distance between letters or characters of a word, or a series of characters typed, without the use of the space bar, will be one-quarter unit distance. The space bar is arbitrarily set to allow four units movement to the carriage.

Fig. 32 illustrates the relation of the type to the printing line PP. It will be observed that the letter m (either upper or lower case. is centered with reference to the printing line. This letter is five and three-quarters units wide and the carriage spacing allowed for this letter m is six units, there being a difference of onequarter unit between the actual width of the letter and the carriage spacing allowed, oneeighth of this diiference is in front of the letter and one-eighth of this difference is after the letter. The letter n, for example, is offset from the printing center line and the carriage spacing allowed for this letter n is four units whereas the letter itself is three and three-quarters units wide. The letter i is further offset from the center of the printing point and the carriage spacing allowed for this letter i is two units whereas the letter itself is one and three-quarter units wide. It will be observed that the front edges of all letters are the same distance from the center of the printing point and that the carriage spacing is so arranged as to allow oneeighth of a unit in front of each letter and oneeighth of a unit following each letter.

Referring now to the diagrams (Figs. 27, 28, and 30) it will be observed that in Fig. 27, the letters of each word are spaced from center to center an equal amount, whereas in the diagram, Fig. 28, each letter occupies a space equivalent to its width and the center to center distance of the letters, therefore, vary dependent upon the width of the associated letters, but that the spacing between letters of each word is constant. The letter T having been printed, the carriage escapes five units (according to Fig. 30) and stops. The letter h is next printed and since there is a one-eighth unit space following the letter T, and a one-eighth unit space preceding the letter h, the distance between these letters will therefore be one-fourth of a unit. The carriage now escapes four units and stops. The letter "e is then printed with a space of one-quarter unit between the h and the e. The space bar is now operated and the carriage moves a distance of four units. Since there is a one-eighth unit after the e and a one-eighth unit preceding the W, the space between words will, therefore, be four and one-quarter units. The W is now typed and the carriage escapes six units and stops. The i is next typed and the carriage escapes two units, with one-quarter unit between the spacing of the W and the i, and so on for the remainder of the letters typed.

From the foregoing, it will be observed that in order for the characters to be printed in the proper relation after the carriage has moved for the letter printed, and with the printing occurring while the carriage isstationary, it is necessary that the forward edges of all the letters shall be exactly the same distance from the center of the printing point. This distance may bear any desired relation to the center line of the printing point, but it has been found desirable to arrange the widest letters, for example, the M and W so that the center of the printing point passes through the middle of the wide letters. This point having been established, it then be comes necessary to offset all narrower letters so that in any event, the front edge of each letter or character, regardless of its own width, is always a predetermined constant distance from the center line of the printing point Fig. 32.

Similar constant relationships of the front edges of the letters to the center line of the printing point are used for different carriage spacings which are associated with different width type fonts; for example, if the type font A as above referred to, requires a basic carriage spacing of ten spaces to the inch, the distance of the front edge of each letter of this font Afrom the center of the printing point will be constant, but if the type font D which requires sixteen spaces per inch of carriage movement be substituted, the said constant distance will be less. In all cases, however, the front edges of the letters of each font are always the same distance from the center of the printing point. This is because anism will move the carriage proportionally different amounts dependent upon whether the carriage is set to escape ten spaces to the inch or whether the carriage movement is set to escape sixteen units to the inch. From the above, it will appear that the present differential spacing the arbitrary units chosen for the spacing mechfor letters is applicable to fonts of different widths and to carriage spacing movements of different normal amounts.

The machine herewith illustrated in the drawings is of the key controlled shuttle type where the printing impression is formed by the impact of a printing hammer and is known in the art as the Varityper. It comprises a main frame I which carries the mechanism of the machine. Reference will now be made more especially to Figs. 1 and 2. Type keys 2 (only a few being illustrated) are mounted on a pivot bar 4 supported by the main frame I. These type keys 2 at their front ends carry finger buttons 5 and at the rear ends cooperate with actuator bars 6 (one of which is shown in Fig. 2) to operate the actuators I to swing the shuttle carrier 8 which oscillates the shuttle 9 to position the proper type at the printing point. Stop rods l0 are provided over each type key lever 2 to engage the swinging arm H to definitely position the proper type at the printing point when a type key is operated. This mechanism is old and well known in the art and will not be described in detail. See patent to Trego No. 1,880,592, October 4, 1932.

The universal bar l2 actuates the ribbon mechanism comprising ribbon spools M, a ribbon guide 15, and other mechanism which is not illustrated in detail since this construction is also well known in the art. See patent to Trego No. 1,930,068, October 10, 1933.

The paper carriage I6 is provided with antifriction rolls ll which travel upon the carriage supporting rod l8 as the carriage tends to move to the left under the influence of the carriage spring drum I9 (Fig; 1) which is connected by the metal band 20 with the carriage. This mechanism is also old and well known in the art and therefore will not be described in detail. See patent to Oswald No. 1,985,419, December 25, 1934.

The machine is provided with shift keys 2| designated as Fig. which position the characters illustrated in the table of Fig. 31 for operation at the printing point, and with shift keys 22 designated as Cap which position the font of capital letters for operation at the printing point. This mechanism is also well known in the art and will not be described in detail. See patent to Spaloss No. 2,051,112, August 18, 1936.

The present invention having to do more especially with the spacing movements of the carriage, comprises a variable space control whereby the carriage of the machine may be given its predetermined normal carriage spacings. This mechanism (Figs. 1, 2, 15, and 16) comprises a shaft 24 slidably and rotatably mounted in bearings in the main frame and controlled by a hand lever 25 which is adapted to be engaged in various notches 26 in the index plate 21. The rear end of the shaft 24 carries an arm 28 provided with an offset plate 20 adapted to engage a rack lifting holding dog 38 to cause the dog to engage in the teeth of the rack 34 and lift the same whereby it may be lowered into engagement with a particular carriage gear wheel 82, 3 1, or 35 mounted on the escapement shaft. This dog 30 at the same time by interlocking with the teeth of the rack 3| prevents the power of the spring in the carriage drum 1.! from moving the carriage while the rack is disengaged from the carriage gear wheels. A lever 35 pivoted at 3'! on the main frame is connected at one end with a sleeve 38 carried by the shaft 24 and at the other end engages a groove 39 in a grooved disc 40 which is integral with the carriage gear wheels 32, 34 and 35. This group, namely, the grooved disc 40, and

the carriage gear wheels 32, 34, and 35 are an integral unit and are slidably mounted upon the escapement shaft 4| and'are compelled to rotate with this shaft by key 42. By moving the hand lever 25 from one notch 26 to another in the index plate 21, the corresponding carriage gear wheel 32, 34, or 35 may be caused to slide on shaft 4| and to engage the rack 3|, and when this is done, the normal carriage spacings per inch will be in accordance with the number on the index plate 27. This mechanism is also old and will not be further described in detail. (See patent tto Trego No. 1,918,299, July 18, 1933.)

The differential letter spacings comprising a major feature of the present invention may be divided into two general groups, namely, the mechanism for selection by the type key levers of the proper escapement, and the group of mechanisms comprisin the escapement mechanism itself.

Referring now to the selective mechanism associated with the type keys (see also Fig. 21), it will be observed that each type key lever is provided with depending rods and in most cases, there are three of these rods associated with each type key. The rods will be designated Ia, IIa, and IVa. There are three universal bars located beneath the lower ends of these push rods, and the universal bars are designated Ib, IIb, IVb. The universal bars Ib, 11-4), and IVb are notched on their upper surfaces with notches 44, 45, and 46 respectively. The push rods Ia, IIa, and IV-a all pass through a movable rod plate 4'! (seeFigs. 1 to '7 inclusive). As shown in Fig. 6, this rod plate is slidable in an are over the universal bars Ib, II-b, IVb, for a short distance due to the mounting of the plate 41 upon stub screws 48 (Figs. 3, 4, and '1 which are secured to the top plate 49 that is fixedly mounted in the machine frame and is provided with an arcuate opening 50 through which the push rods extend. The rod plate 41 is provided with an upstanding pin (Figs. 6 and 7) which rests between the ends of the spring arms 52 and 54 that are pivoted at 55 and 56 to the top plate 49. These arms are normally pulled together by the tension spring 51, thus causing the arms to bear against the stationary pin 58 mounted in the top plate 49 and thus normally align the upstanding pin 5| on the rod plate 41 with the stationary pin 58, thereby centering the rod plate 41 in central position, but allowing a movement thereof either to the right or to the left, of the central position and permitting the arm which has been moved away from the stationary pin 58 to urge the rod plate toward normal central position. The rod plate 4-'| is provided with a forward extension 59 (Fig. 6) that carries an upwardly extending forked bracket 60 (Fig. 3) which extends on each side of a pin 62 carried by a shift bar 64 that is slidably mounted upon stud screws 65 secured to the key comb 66. The stub screws 65 extend through slots 61 in the shift bar 64. The ends of the shift bar are provided with cam surfaces 68 that cooperate with the Fig. shift keys 2| and also with cam surfaces 69 that cooperate with the Cap shift keys 22. It will be observed from Figs. 3 and 4 that when the Cap shift keys 22 are depressed, the shift key levers cooperate with the cam surfaces 69 and move the shift bar 64 in the direction of the arrow X, namely, to the left, and this shifts the rod plate 41 to the left. This moves all of the lower ends of the push rods Ia, IIa, IVa, to the left. By reference to Figs. 3 and 5, it will be noted that when the Fig. shift keys 2| are depressed, the

shift keylevers cooperate with the cam surface 68 and cam the shift bar 64 in the direction of the arrow Y, namely, to the right thereby shifting the rod plate 47 and the lower ends of the push rods to the right. The normal position of the rod plate 41 and the shift bar 64, as previously stated, is in the centralized position as indicated by Figs. 3 and 6.

Referring now to Figs. 21 to 26, inclusive, it will be noted by reference to Fig. 21 that if the type lever L is depressed with the push rods in the position shown in Fig. 21, the push rod II-a will depress the universal bar IIb, whereas the push rods Ia and IVa will descend in notches 44 and 46 in universal bars Ib and IVb without actuating them. Thus, when the type lever L is depressed without the use of either shift key, only the universal bar 11-1) is actuated.

Referring to Fig. 23, which illustrates the push rods connected with the A-key, it will be observed that when the lower case letter a is typed, the push rod IVa depresses the universal bar IVb. The dotted lines representing the push rods to the right of the full line drawing thereof show the position of the push rods when the Fig. shift keys 2| are depressed and it will be observed that the push rods Ia and IIa are in position to depress the universal bars Ib and IIb, when the type key is now depressed, while the push rod IVa will descend in notch 46. The dotted line representation of the push rods to the left of the solid line drawing illustrates the position of these push rods when the Cap shift keys 22 are depressed and it will be observed that the push rods Ia and IV-a are in position to actuate the universal bars Ib and IVb when the type key lever A is now depressed while the push rod IIu. will descend into the notch 45 of the universal bar IIb without actuating the same.

Referring to Fig. 24, which represents the relation of the push rods to the universal bars as to the w-key, it will be observed that normally, the push rods IIa and IVa are in position to depress the universal bars 11-?) and IVb. This same relation is maintained when the Cap shift keys 22 are depressed, but when the Fig. shift keys 2| are depressed, then only the push rod IVa is effective since the push rod II-a will descend in the notch 45 in the universal bar IIb. It will also be observed in this case only two push rods are carried by the wkey.

Fig. 25 represents the push rods carried by the t-key, and in this case, normally, universal bars Ib and II-b will be depressed when the type key lever is depressed. The IVa push rod will descend into the notch 46 in the IVb uni- Versal bar. When the Cap shift keys 22 are effective, universal bars Ib and IV-b are depressed and when the Fig. shift keys 2! are effective, only the IVb universal bar will be depressed.

Referring to Fig. 26 which represents the spacing key, it will be observed that only one push rod 8| is provided and this push rod is always effective on the IVb universal bar regardless of the use of either of the shift keys 25 or the shift keys 22.

By reference to Fig. 22 representing the period type key, it will be observed that only one push rod 11-0. is attached to this key and that this push rod is always effective on the universal bar II-b regardless of the use of the shift keys 2| and 22. I I

The space bar I is provided with arms II and I2 which are pivoted at I4 and I5 to the main frame and the mid portion of the space bar I0 connects with a lever 16 (Figs. 1 and 2). This lever is pivoted at 11 and the rear end of the lever I6 is connected by a link I8- to a rocking lever 79 which is pivoted at 80 in the main frame. A forward end of the rocking lever 19 carries the push rod 8I which as previously explained cooperates with the IV--b universal bar. A tension spring 82 connects the forward end of the rocking lever I9 with the lever I6 near the pivot point center line thereof so that the effect of the spring is to maintain the space lever lifted at its forward end until the rocking lever 19 contacts with the stop 83 to maintain the space lever at the proper height. The universal bars Ib, II -b, IV-b are guided by guide pins 53 (Figs. 3, 5, and 6) and rest upon the forward ends respectively of escapement levers I-c, 11-0, and IVc, Fig. 2. These escapement levers are all mountedupon a pivot rod 80 secured to the under portion of the frame of the machine and these levers extend rearwardly and are connected by escapement links I-d, II-d, and IV--d with escapement dogs I-e, IIe and IVe.

These escapement dogs cooperate respectively with escapement wheels I--- IL-f, and IV- The escapement dogs are mounted upon a pivot pin 85 (Fig. 13) which is carried by the gear box 86 of the hammer operating mechanism that is wound by the electric motor 81 (Fig. 1). This mechanism is well known in the art and therefore will not be described at this time in detail. Referring to Figs. to 14 inclusive and more especially to Fig. 13, it will be observed that the escapement shaft 4| is provided with a disc 88 which is fixedly mounted on the shaft 4|. This disc 88 carries three planetary gears 89 which are mounted to rotate on axles 90 that are riveted to the disc 88. These planetary gears 89 'mesh at their inner peripheries with the sun gear 9| comprising a portion of a tubular member 92 rotatably mounted on shaft 4|. escapement wheel IV- is a shell-like member mounted to rotate on the tubular member 92 and is provided with an internal annular gear 93 which meshes with the outer peripheries of the planetary gears 89. This escapement wheel IV--f is also provided with a ratchet Wheel 90 having the teeth thereof extending in the opposite direction from the teeth of the escapement wheel IVf to prevent rearward rotation thereof during carriage return movement (Figs. 11

and 13). The escapement wheel II- is also mounted for rotation upon the tubular member 92 and is provided with a ratchet wheel 90 with which the dog 91 cooperates to prevent backward rotation of the escapement wheel IIj during carriage return movement. A circular plate 90 is fixedly mounted on the rear end of the tubular member 92. Planetary gears 99 (Figs. 10 and 13) are mounted to rotate upon axles I00 that are riveted to the circular plate 98. These planetary gears 99 cooperate with a sun gear IOI that is integral with the escapement wheel I-f which is mounted for rotation upon the escapement shaft 4| and is retained in position thereon by a journal bracket I02 carried by the gear box 86. These planetary gears 99 at their outer peripheries are in mesh with an annular gear I04 that is integral with the escape- The Each escapinent dog Ie, II--e and IVe comprises two members, a movable dog I05 and a fixed dog I06. Movable dogs I05 are provided with pins I01 with which tension springs I08 are connected to normally hold the movable dogs in engagement with their respective v escapment wheels. When a universal bar is depressed, the rear end of its respective escapement lever is raised. thereby pushing upwardly on its respective escapement link and rocking the corresponding fixed dog I00 in a counter-clockwise direction (Fig. 8). The tail I09 on each fixed dog I06 causes the operated dog to remove the movable dog I05 from engagement with the teeth of its respective engagement wheel. The fixed dog I08, however, is now in the path of an oncoming tooth of the escapement wheel before the escapement Wheel is entirely free from the movable dog I05 and the relation between the fixed dog I98 and the movable dog I05 is such as to permit a very slight movement of the escapement wheel after the movable dog I05 has been disengaged from the escapement wheel which is being held by the fixed dog I06 (Fig. 9). When the fixed dog I05 releases the escapement wheel, it is reengaged by the movable dog I05 and the escapement wheel has turned one tooth.

The differential letter spacing escapement mechanism operates in the following manner. The carriage spring drum I9 through the metal band 20 imposes a pull on the carriage rack 3| which through the respective gear wheel 32, 34, or 35 which is engaged by the rack, thus imposes a turning moment on the escapement shaft 4|. This turning moment is resisted by the movable dogs I05 which prevent the escapement wheels from rotating. The turning moment, due to the spring drum I9, is transmitted from the shaft 4| initially to the disc 88 which carries the planetary gears 89. The outer peripheries of these plane tary gears 89 impose a turning moment on the annular gear 93 connected with the escapement wheel IVI. Since this gear 93 is held stationary by the respective movable dog I05, a turning moment is transmitted to the sun gear 9I on the tubular member 92 through the circular plate 98 to the planetary gears 99. The outer peripheries of these planetary gears 99 engage the annular gear I 04 connected with the escapement wheel II-,f which likewise is held stationary by its respective movable dog I05 and the sun Wheel for the planetary gears 99 impose a similar turning moment on the escapement wheel I-f which is held by its movable dog I05.

Assume that the escapement dogs Ie are actuated to release the movable dog I05, and that the fixed dog I00 is operated to catch and then release the escapementwheel so that the movement of wheel I-f is transmitted through the planetaries 99 of the circular plate 98, the tubular member 92, the sun gear 9 I, the planetaries 89 to the disc 88 and thence to the escapement shaft M. This movement is one unit, and allows one unit of movement to the carriage.

Assuming escapement dogs IIe are actuated to allow one tooth of movement to the escapement wheel II- the rotative motion will be transmitted through the planetary gears 99 to the circular plate 93, the tubular member 92, the sun gear 9|, the planetary gears 89 to the disc 88 and thence to the escapement shaft 4|. This angular movement produced by one tooth escapement of the escapement wheel II] is two units, and allows two units of movement to the car- .riage.

Assuming that the escapement dogs IVe are operated to permit a one tooth escapement of the escapement wheel IV the motion is transmitted from the escapement wheel IV-;f to the planetary gears 39 and to the disc 88 and thence to the escapement shaft 4 i. This movement permitted by one tooth escapement of escapement wheel IV-] is four units, and allows four units of movement to the carriage.

If escapement I] and II1 are simultaneous-- 1y operated, the result is the sum of one unit and two units, namely, a total carriage movement of three units. If escapement wheels I--,f IV-) are simultaneously operated, the result is a carriage movement of five units. If escapement wheels IIf and IV are simultaneously operated, the totalmovement of the carriage is six units; and if all the escapements are simultaneously operated, the result is a total carriage movement of seven units.

Escapement wheels If and II provided with twenty teeth on their periphery. Escapement wheel IVf is provided with thirty teeth on its periphery. Both sun gears 55 and till each have twenty-four teeth. The annular gears 93 and 5% each have forty-eight teeth, and the gears of both sets of planetary gears SS and 9% have twelve teeth on each gear.

The ratchet wheel 94 on the escapement wheel IV- is provided with thirty teeth. The ratchet wheel 9% on the escapement wheel II- has twenty teeth. The purpose of the ratchet wheels 94 and 96 and their respective holding dogs 95 and 91 are to hold the escapement wheels 11- and IVf stationary during a carriage return. The reason for this is that by permitting the escapement wheel If only to turn backwardly when the carriage is returned is to assure the operator that the carriage will always be returned to the same point so that the starting points of each line in a column of lines will all be in a true vertical line. This might or might not be the case if all the escapements were permitted to rotate backwardly when the carriage is returned.

The machine is provided with a tabulating key H (Fig. 1) which actuates tabulating lever Ill (Figs. 1 and 2) that pushes upward on the tail H2 (Fig. 8) of the movable dog I of the escapement I,f. This tail H2 is provided only on the movable dog I65 of the escapement dog I-e. The operation of the tabulating key HI] releases the escapement wheel I-f only so that the carriage is free to move and tabulation occurs.

The hammer mechanism for driving the paper and the printing ribbon against printing type positioned at the printing point to cause a printing impression is illustrated in Figs. 17, 18, 19, and 20 of the drawings and comprises a construction substantially the same as that shown in Trego Patent No. 1,965,677, patented July 10, 1934. The universal bar I2 (Figs. 2 and 17), previously referred to, not only operates the ribbon mechanism but also trips the hammer release, on the down stroke of a type key. In other words, the printing operation in the present machine occurs on the down stroke of the letter or character type key and the carriage escapement is completed on the upstroke of such a key.

From the foregoing, it will be observed that when the words illustrated in Fig. 27 of the drawings, comprising the words The Wind is, is written'on the ordinarytypewriting machined-he letters will be spaced equally from center to center a predetermined definite amount, but the spacing between letters is Variable, dependent on the width of the letters. When these same words are typed on a, machine comprising the present invention, the letters of a word are no longer spaced equal distances from center to center, but the spacing between the letters of each word are constant predetermined distances, as is the situation where words are printed from typographical type.

The diagram in Fig. 29 illustrates in the horizontal lines H5, H6 and III, the relationship between certain typical letter keys in the keyboard with reference to the escapements actuated when these letters are typed, and the xs in these horizontal lines indicate the escapements actuated, for example, in the group under the letter A where a lower case a is typed, the IV- escapement wheel is actuated. Where an upper case A is typed, the escapement 1- and IVJ are simultaneously actuated; and where the character carried on this key lever (which character is a quotation mark), is typed, then escapements I- and II are actuated. This explanation applies with the same understanding to the other letters and characters designated in this chart shown in Fig. 29.

From the foregoing, it will be observed that while the mechanism for differential letter spacing is herewith illustrated in connection with a shuttle type of typewriting machine, it is primarily a carriage control mechanism and is therefore capable of association with any other kind of printing mechanism operative in a typewriting machine.

It is also to be noted that the present differential letter escapement mechanism is of such character as to be capable of association with different standard carriage spacings, which render the present mechanism particularly adaptable for use with typewritting machines intended to produce master sheets that are lithographed for various publications where it frequently is desirable to change either the size or the style of the type fonts for headings, emphasis, etc.

From the foregoing, it follows that the present differential letter spacing mechanism is of a flexible character adapted for many desirable uses in the typewriter field.

What I claim is:

1. In a typewriting machine, in combination, a movable paper carriage, a plurality of differential letter space escapements operatively connected with said paper carriage, a plurality of universal bars operatively connected with said escapements, type keys in a keyboard, a plurality of push rods carried by said type keys, said universal bars being provided with notches, and means to shift said push rods relatively to said notches to determine the effective operation of said push rods on said universal bars when the type key is operated.

2. A typewriting machine as in claim 1, in which there are shift keys, and in which the means to shift the push rods comprises: a shiftable guide plate through which the ends of the push rods extend, and means actuated by the shift keys to shift the guide plate.

3. In a typewriting machine, in combination, a movable paper carriage, a plurality of difierential letter spacing escapements arranged in series and adapted to control the letter space movements of said carriagaand means for retaining all of said escapements stationary e'xcept one when the carriage is moved from left to right for return carriage movement.

4. In a typewriting machine, in combination, a movable paper carriage, a plurality of differentially operated letter escapement wheels for controlling the letter spacing movement of said carriage, said wheels being arranged in series, movable dogs for each of said escapement wheels, tabulating mechanism, and means operated by said tabulating mechanism to release the movable dog of one only of said escapement wheels to permit freedom of movement of said carriage.

5. In a typewriting machine, in combination, a movable paper carriage, differential letter spacing mechanism comprising three letter spacing escapement wheels, one of said letter spacing escapement wheels being adapted to permit a movement of one arbitrary unit to the carriage when said escapement is operated, the second escapement wheel being adapted to permit two r of said units movement to said carriage when said second escapement wheel is operated, and the third escapement wheel being adapted to permit four of said units movement when said third escapement wheel is operated, escapement dogs for controlling each of said escapement wheels, means normally tending to move said carriage from right to left, means to prevent backward rotation of the second escapement wheel and means to prevent backward rotation of the third escapement wheel whereby the first escapement wheel only is permitted to rotate backwardly when the carriage is moved from left to right.

6. In a typewriting machine, in combination, a movable paper carriage, differential letter spacing escapement mechanism for controlling the movement of said carriage for letter spacing, a plurality of universal 'bars having notches therein and operatively connected with said escapement mechanism, a plurality of type keys mounted in a keyboard, depending push rods extending from said type keys into operative relation with said universal bars, a shiftable guide plate through which the lower ends of said push rods extend, and key controlled means to shift said guide plate to change the relation of the lower ends of said push rods relative to the notches in said universal bars.

7. In a typewriting machine, in combination, a movable paper carriage, differential letter spacing escapement mechanism for controlling the letter space movement of said carriage, a plurality of universal bars operatively connected with said escapement mechanism, said bars being provided with openings, a plurality of type keys in the key-board of said machine, push rods associated with said type keys and in operative relation to said universal bars, a guide plate through which the ends of said push rods extend, printing mechanism having a printing point, means comprising shift keys to shift the type at said printing point, and means operated by said shift keys to shift said guide plate to change the relation of the ends of said push rods relative to the openings in said universal bars.

8. In a typewriting machine, in combination, a movable paper carriage, differential letter spacing mechanism comprising escapement Wheels adapted to control the movement of said carriage for letter spacing, a plurality of universal bars being the same in number as the number of escapement Wheels in said escapement mechanism, said universal bars being operatively connected with said escapement mechanism to operate the same, said universal bars being provided with openings, a plurality of type key levers arranged in a keyboard in said machine, push rods carried by said key levers, a guide plate adapted to guide the free ends of said push rods, a shift key to shift the type at the printing point, and means operated by said shift key to shift said guide plate to change the relation of the ends of said push rods relatively to the openings in the universal bars wherein a push rod positioned in line with an opening is ineffective to operate a universal bar when the associated key lever is depressed.

9. In a typewriting machine in combination, a movable paper carriage, a differential letter spacing escapement mechanism for controlling the movement of said carriage for letter spacing, a plurality of universal bars operatively connected with said escapement mechanism, a plurality of key levers arranged in a keyboard, push rods associated with said key levers and being adapted to form the connection between said key levers and said universal bars, a guide plate for guiding said push rods, said universal bars being provided with openings, a shift key to shift the type at the printing point, and means operated by said shift key to shift said guide plate to change the relation of the ends of said push rods relative to the openings in said universal bars.

CHARLES W. NORTON. 

